The contestants were tasked with finding a word from the letters R, V, O, E, P, T, E, R, S on Countdown.

Rachel Riley was unable to keep a straight face as the player revealed his answer during the letter game.

One of the contestants said he had thought of an eight letter word which was “perverts”.

Nick Hewer appeared unfazed by the spelling and asked Susie Dent if there were any other words which could be spelt.

Adrian Chiles, who was sat next to Susie in the Dictionary Corner, joked: “We have got something less unsavoury than that!”

But the same couldn’t be said for Rachel who struggled to hold back the laughter as she assembled the letters on the board.

The mathematician later shared a photo of herself standing next to the word with a very humorous look on her face.

She captioned the photo shared other Twitter: “Dear internet, a screengrab for your bottom drawer. You’re welcome @C4Countdown.”

Many of Rachel’s 591,000 followers loved her facial expression in the snap with many commenting on her list.

One person replied: “Your expression is perfect x.”

Another said: “That wasn’t on TV was it,” alongside laughing crying emojis.

A third said: “The face that goes with it is priceless.”

Rachel looked incredible as always on the Channel 4 show as she stunned in a light pink knee-length dress.

The figure-hugging number accentuated her incredible figure and she elongated her pins with a pair of high-heels.

Rachel’s blonde locks were styled in loose waves and she wore a poppy on her chest.

Earlier this month, Rachel was left red-faced once again after a very rude word was spelt out on the board.

During an episode, Susie offered the word “Budgie”, which left the letters C, U, M on the top row during one of the challenges.

The former Strictly Come Dancing contestant couldn’t believe the word which had been left as she stood next to it and smirked at the camera.

The mathematician uploaded the snap alongside the caption: “Anyone in need of a new creative insult, @C4Countdown is at your service! Come on, we all know one…”

Countdown airs weekdays on Channel 4 at 2.10pm.